The disclosed embodiments of the present invention relate to generating a resized image, and more particularly, to content-adaptive image resizing methods and related apparatuses thereof.
Camera modules have become popular elements used in a variety of applications. For example, a smartphone is typically equipped with a camera module, thus allowing a user to easily and conveniently take pictures by using the smartphone. However, due to inherent characteristics of the smartphone, the smartphone is prone to generate blurred images. For example, the camera aperture and/or sensor size of the smartphone is typically small, which leads to a small amount of light arriving at each pixel in camera sensor. As a result, the image quality may suffer from the small camera aperture and/or sensor size.
Besides, due to lightweight and portability of the smartphone, the smartphone tends to be affected by hand shake. Specifically, the shake of the smartphone will last for a period of time. Hence, any picture taken during this period of time would be affected by the hand shake. An image deblurring algorithm may be performed upon the blurred images. However, the computational complexity of the image deblurring algorithm is very high, resulting in considerable power consumption. Besides, artifact will be introduced if the image deblurring algorithm is not perfect.
Moreover, a camera module with an optical image stabilizer (OIS) is expensive. Hence, the conventional smartphone is generally equipped with a digital image stabilizer (i.e., an electronic image stabilizer (EIS)). The digital image stabilizer can counteract the motion of images, but fails to prevent image blurring. In addition to the camera shake, the movement of a target object within a scene to be captured may cause the captured image to have blurry image contents.
As mentioned above, the image capture result may be affected by hand shake and/or movement of the target object. It is possible that one partial region of the captured image is blurry, while another partial region of the captured image is clear. Hence, applying the same filter setting to the whole captured image may fail to obtain an output image with optimal quality.
As a result, when the camera module is affected by hand shake and/or there are moving objects within the scene to be captured, still images generated by the camera module under a photo mode or video frames of a video sequence generated by the camera module under a video recording mode would have blurry image contents.